Following the principles laid out on the Seed Planting Depths &
Distances webpage here is a step by step guide on how to
plant large seeds (such as peas or beans) in a row.

Plant the seeds at half the distance recommended on the seed packet
and at a depth outlined in the
Seed Planting Depths section.

As the seeds develop into seedlings some will not germinate and some
may be eaten or damaged by pests.

When the seedlings are six to ten centimetres high thin out to
the desired spacing for the mature plants. If there are gaps in your
line caused by seeds that didn't germinate or plants eaten by pests
then transplant some of your unwanted seedlings to these gaps. But
make sure you water them well with a liquid fertilizer to ensure
that they strike. And if the weather is hot then wait until
there is some cooler weather before transplanting them.

By the time the seedlings have matured into adult plants they should
be evenly spaced at the correct distance with no gaps in the line.